Primary cell wall is an essential cell structure for plant playing major roles in plant growth, differentiation, and stress responses. Here we demonstrate that a group of AP2-ERF transcription factor regulates primary cell wall formation and can induce massive accumulation of it in empty fiber cell of the nst1-1 nst3-1 mutant lacking secondary cell wall in Arabidopsis. The transgenic plants expressing one of the AP2-ERF transcription factors fused with VP16 transcriptional activation domain under the control of NST3 promoter in the nst1-1 nst3-1 mutant showed similar level of cell wall contents with wild type by the massive accumulation of cell wall which lacks lignin and xylan. The transgenic plants showed 70% higher saccharification efficiency than wild type. Gene expression analysis using microarray revealed that genes related to primary cell wall were highly upregulated in the transgenic plant. Moreover, chimeric-activator of the AP2-ERF transcription factor accelerated cell wall regeneration of mesophyll protoplast of Arabidopsis while the chimeric-repressor retarded it. These data suggest that the group of AP2-ERF transcription factor is key regulator of the primary cell wall formation in plant and could be employed to produce massive cell wall with readily extractable feature. Overall design: Transcriptomes of stem of NST3pro:ERF035-VP16 nst1-1 nst3-1 plant and that of nst1-1 nst3-1 plant were measured to see their difference.